Hey dude, here's the gist:
y = log<sub>e</sub>x ---------> x = e<sup>y</sup>
I'll take that question from the cambridge 18 b) 28 as an example.
(Find ∫ lnx dx between 1 and a)
At x=a , y=lna . Draw the perpendiculars from the x and y axis to (a,lna) and think in terms of a...